In the PBS documentary, "League of Denial: The NFL's Concussion Crisis,"one of the most troubling allegations is that the NFL actively worked to keep the brain of Junior Seau out of the hands of research teams that have been critical of the league's efforts in the past.

Seau is arguably the most famous face in the NFL's concussion crisis, having committed suicide with a gun shot wound to the chest — leaving his brain intact.

After he passed away, Dr. Bennet Omalu, who was the first researcher to discover Chronic Traumatic Encephalopathy (CTE) in the brain of an ex-NFL player, received consent from Seau's son to sample Seau's brain to search for signs of brain disease.

However, according to "League of Denial" author Steve Fainaru, once the NFL learned that Omalu was going to autopsy the brain, they contacted Seau's son and informed him that "Omalu's research is bad ... and that he is essentially unethical."

In the documentary, the NFL defended its recommendation of donating the brain to NIH based on "getting it into the hand's of good science." However, in addition to bypassing Omalu's group, the NFL also bypassed the CTE research team at Boston University, the same group the NFL had previously declared as the "preferred" brain bank of the NFL.

According to author Mark Fainaru-Wada, the NFL allegedly "very directly worked" to keep the brain out of the hands of those groups and accomplished this by "speaking badly" about them.

In addition to CTE research in NFL players, the one thing Omalu's group and the Boston University group have in common is that they clashed with the NFL in the early days of concussion research.

But the question remains: At what point does the NFL's donation of millions to concussion research go from good-hearted effort to fix a problem to money being used to keep the story under control and the important voices under the league's influence?